JP-2002-290138 A describes an antenna device formed of multiple radiation elements that are earthed to the ground plane. This antenna device includes a first radiation element and a second radiation element. Each of the two radiation elements includes a turnup portion so that two side portions are formed in approximately parallel with each other. Further, each of the two radiation elements includes a bending portion so that the two side portions are formed in approximately parallel with a ground plane. Further, the two radiation elements adjoin approximately parallel with each other while being grounded to the ground plane.
In this antenna device, the entire second radiation element is disposed separately outside the first radiation element, so that achievement of multiple-frequency resonance requires widths of the radiation elements and an interval gap between the radiation elements. The antenna device thereby becomes large-sized.